Dust filter for vacuum driers



Aug. 15,1950 G. STEVENSON DUST FILTER FOR VACUUM DRIERS Filed April 17, 1947 INVENIUR GUST/E STEVENSON Brad A QM .ATI'URNBYI Patented Aug. 15, 1950 DUST FILTER FOR VACUUM panties Gustie Stevenson, Philadelphia, Pa.,.assignor to F. J. Stokes Machine Company, a corporation of Pennsylvania.

Application April 17, 1947, SerialNo. 742,161

Claims. (01. 1'83-'51) This'invention relates to dust filters to be applied especially for the purpose of removing dust or other particles from the vapors or gases drawn from a vacuum dryer and for preventing such particles from reaching the vacuum pump.

My dust filter is of the type to be mounted upon a vapor 'outlet of the dryer located at the top thereof and positioned so that accumulated dust or particles may be returned to the dryer by shaking or agitating the filter. .For this. purposethe filter unit of. my filter is formed as a bag and is mounted in inverted position.

An object of my. invention is to devise a filter construction in which the filtering unit may be easily removed. for repairs or for replacement of anew unit.

A further object of the invention is to devise an arrangement for vibrating the filter unit while the unit is mounted within a vacuum-tight casing.

Other objects will become apparent from the following description taken in connection with the accompanying drawing, the single figure of which a side'view of the filter construction, the lefthalf of the view being shown in section and the right half in elevation.

Referring to the drawing;my improved filter involves a tubular casing I having an annular flange 2 at its lower end'by which the casing is mounted upon the vapor outlet 3 of the dryer, not shown. The. outer portionof the flange 2 isused to make a vacuumetight joint with a flange on.

outlet 3, and the portion ofthe flange 2 extend ing inwardly beyond the wall of casing I serves as; a;support for the filter unit. Casing I preferably isin the form of a cylindenalthough it might have other shapes.

The upper end of casing I is closed by a removable cover orclosure formed of a plate 4' seated on an annular flange 5 at the upper end of the casing I, with a sealing ring 4a interposed; the ring 4a" may be formed of rubber or other suitable material and preferably has a locking portion extending into an annular groove formed in-thecover plate 4; The cover plate is hinged to the casing I by means of an arm 6 pivotally connected to a bracket I mounted on the casing I, and the plate t is pivotally connected to the arm 6 by 'means of a pair of brackets 41). The arm 6 extends entirely acrossthecover plate 4 from the bracket '8 and the outer end of the arm is bifurcated to receive an eye-bolt 8 pivotally,

mounted upon a bracket 9 carriedby the casing I. A hand wheel Iii. has threaded engagement with the upper end of the eye-bolt B, and by means of this construction the cover plate 4 may be tightly clamped in position to seal the upper end of the filter casing, The arm 6' extends to the right of bracket 1 and maybe provided with a counterweight Ga mounted for adjustment thereon.

The'filtercasing'is provided with an outlet I I formed in its vertical wall and extending horizontjally from the casing near. the upper end thereof.

The lower portion of the filter casing I is provided with a steam jacket I2 through which steam is passed by means of an inlet connection [2a at the top of the jacket and an outlet connection I2b at the bottom thereof.

The filter unit is formed of a filter element in the form of a fabric bag having a supporting frame, and is Supported within the casing I on the flange. 2. The frame for supporting the filter bag includes a short cylindricalring I3 having an external annular flange I4 secured to the lower end thereof and which is seated upon the inner part of flange 2. of the casing I with a ring of sealing material. I5 interposed. Preferably, the sealing ring I 5. has a locking. portion extending into an'annular groove formed in the lower face of the flange I4. A number of vertical rods I6 spaced about the ring I3 have their lower ends secured to the ring I3 in any suitablemanner, preferably by welding the ends of the rods to the inner surface of the ring I3; The rods I6 preferably are formed of tube. or pipe stock, with the ends flattened as shown in the drawing. An annular ring I7. formed of an angle section consisting of a vertical flange and a horizontal flange is suitably secured to the upper ends of the rods I6, as by welding; The lower ends of certain of the rods I6 may be extended downwardly below the flange I l and turned inwardly as shown at IGa to serve as guides for centering the flange I4 on the flange 2. Any other construction for centering the flange I4 on its seat may be used.

The filter bag I8, preferably formed of canton flannel with the nap arranged inside of the bag, is supported by the frame just described, in an up-side down position. The neck of the bag is securely clamped around the outside surface of the ring I3 by means of a clamping band I8a.

The bag supporting frame is securely clamped on the seating flange 2 by means of a clamping structure now to be described. An annular clamping head in the form of an angle ring I9 fits over the upper end of the filter unit and is provided with a number of radially extending arms [9a secured to the outsidethereof. These arms are provided with slots in the side edges thereof for receiving the upper ends of four long eye-bolts 20 which are anchored at their lower ends to studs 2i mounted on the inside of easing I' near the lower end thereof. The bolts 25) are provided with clamping nuts 20a threaded on their upper ends, and it is desirable toprovide some means for preventing removal of these nuts while permitting adjustment downwardly to clamp the filter unit in position. The clamping ring I9 is provided with a pair of handles 22, 22 located on opposite sides thereof and by which the ring, after loosening of the nuts 20a, may be removed from the casing I by rotating the ring until the arms Illa disengage the bolts 28, and then lifting the clamping ring vertically upward through the open end of the casing. It. is not necessary to twist or rotate the ring I9 to disengage it from bolts 20, since the upper ends of the bolts' may beswung out of engagement with arms 19a. After the clamping ring I9 has been removed, the filter unit may also be removed through the upper end of the casing l for replacement of a new unit or a new bag.

It will be understood that the outlet 3 of thedryer is a vertical outlet positioned at the top of the dryer so that the filter bag 18 is positioned directly above the dryer. Vapors or gases drawn from the dryer pass upwardly through the open lower end of the bag 18 and through the sides of the bag or through the central part of the bottom thereof, and then pass out through the outlet ll of the filter casing leading to the vacuum pump. Any dust or other particles carried by the vapors or gases are deposited on the inside a 2d may be mounted on the outside of the casing 6 opposite the upper end of the filter unit, and vibrations may be transmitted to the clamping ring is or to any of the eye-bolts 20, by means of a rod passing through a suitable stuffing box 26 provided in the wall of the casing. The driving rod 2'5 may be connected to the ring 19 or to one of the eye-bolts 2d by a releasable connection, or it may be arranged so that the end of the rod merely comes in contact with one of these elements in a manner to vibrate it. The eye-bolts 2s? constitute tension elements or clamping the filter unit on the seating flange 2 of the filter casing. Due to the fact that these tension rods 20 are relatively long,.these rods and the upper end of the filter frame are free to be vibrated by the vibrator 261, and thus remove the deposited material as it accumulates. It will be understood that the supporting frame for the filter bag is of a resilient construction to permit the vibration just described.

it is preferred that all parts of the filter exposed to the vapors or gases be constructed of stainless steel or other non-corrosive metal.

I claim: 7

1. Afilter construction comprising a vertical tubular casing open at both ends and havingan annular internal flange near the lower end, a removable cover for the upper end of said casing, a resilient annular frame insertable through the upper end of said casing and seated on said annular flange, an inverted filter bag surrounding said resilient frame, means for releasably clamping said frame to said annular flange comprising a clamping head removably supported on the upper end of said frame, a plurality of tension members spaced about said clamping head between said bag and said casing and being con-v nected at their upper ends to said head and at their lower ends to fixed points of support adjacent the lower end of said annular frame, a rod extending through the wall of said casing adjacent the upper end of said frame and being mounted for longitudinal reciprocation, and a connection from the inner end of said rod to.

said clamping head for imparting lateral vibrations to the upper end of said frame through said clamping head.

2. A filter construction according to claim 1 4 wherein said annular frame comprises an annular ring seated cnsaid internal flange, a plurality of vertical members spaced about said ring and secured to said ring at their lower ends, and a ring secured to the upper ends of said vertical members.

3. A filter construction comprising a vertical tubular casing open at both ends and having an annular internal flange near the lower end, a removable cover for the upper end of said casing, a resilient annular frame insertable through the upper end of said casing and seated on said annular flange, means for clamping said frame upon said annular flange comprising a clamping head carried on the upper end of said frame and a plurality of tension members spaced about said head between said frame and said casing and connected to fixed points of support near the lower end of said frame, the upper ends of said tension members passing through holes in said clamping head, and releasable clamping devices carried on the upper ends of said tension members for clamping said frame on said flange.

l. A filter construction according to claim 3 and including a rod extending through the wall of said casing adjacent the upper end of said frame and connected to one of said tension memhers below said clamping head, said rod being mounted for longitudinal reciprocation to impart lateral vibration .to said frame through said clamping head.

5. A filter construction comprising a vertical, cylindrical casing open at both ends, an annular plate secured to the lower end of said casing and providing an external coupling flange and an internal annular flange at the lower end of said casing, a removable cover for the upper end of said casing, a cylindrical filter unit insertable through the open end of said casing and having its lower open end seated upon said internal flange and having its upper end closed, means for clamping said filter unit in position on said internal flange comprising a clamping head carried by the upper end of said filter unit, a plurality of vertical clamping rods arranged around said filter unit within the space between said unit and said casing, said clamping rods being connected at their lower ends to fixed points of support adjacent the lower end of said filter unit and having their upper ends extending through holes formed in said clamping head, removable clamping devices carried by the upper ends of said clamping rods and pressing said clamping head against the upper end of said filter unit, and a vibrator rod secured to one of said clamping rods near the upper end thereof and extending horizontally through the wall of said casing for imparting lateral vibrations to the upper end of said filter unit.

GUSTIE STEVENSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name 7 Date 984,810 Green Feb. 21, 1911 994,462 Harrold June 6, 1911 1,322,361 Sherman Nov. 18, 1919 1,602,345 Eiben Oct. 5, 1926 1,747,131 Parsons Feb. 11, 1930 1,829,068 Smith Oct. 27, 1931 2,014,298 Schneible Sept. 10-, 1935 2,219,567 Spielman Oct. 29,1910 

